21121330 has 16 divisors (see below), whose sum is σ = 38828160. Its totient is φ = 8268592.

The previous prime is 21121319. The next prime is 21121333. The reversal of 21121330 is 3312112.

It is a super-2 number, since 2×21121330² = 892221161937800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121330.

It is not an unprimeable number, because it can be changed into a prime (21121333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22000 + ... + 22939.

It is an arithmetic number, because the mean of its divisors is an integer number (2426760).

Almost surely, 2^21121330 is an apocalyptic number.

21121330 is a deficient number, since it is larger than the sum of its proper divisors (17706830).

21121330 is a wasteful number, since it uses less digits than its factorization.

21121330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44993.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21121330 is about 4595.7948170039. The cubic root of 21121330 is about 276.4227313911.

Adding to 21121330 its reverse (3312112), we get a palindrome (24433442).

The spelling of 21121330 in words is "twenty-one million, one hundred twenty-one thousand, three hundred thirty".